Re: non portable sed scripts

[Paul Eggert]

Ralf Wildenhues <address@hidden> writes:

> We check the 99 commands limit, but
> not the [4000] characters limit any more...  :-/

But the 4000-character limit is documented by Autoconf to be a limit
on the length of lines of sed's input data, not a limit on the total
size of the sed script.

However, it turns out that we check the 99 commands limit incorrectly,
as the sed script in question contains 100 commands.  I installed this
patch.  It's conceivable that this patch fixes the problem; it'd be
nice to test this.

I found what appear to be some other off-by-one issues that cause
98-line scripts instead of 99, but these are not bugs so I didn't fix
it.  Also, that code is too hairy (does anybody understand it other
than its author? I sure don't) so I didn't want to mess with it.

In the long run we're probably better off finding a working 'sed' than
continuing to cater to broken ones.

2006-05-19  Paul Eggert  <address@hidden>

        * lib/autoconf/status.m4 (_AC_OUTPUT_HEADER): Fix off-by-one bug
        that caused config.status to generate 100-command sed scripts; the
        portable limit is 99.

--- lib/autoconf/status.m4      19 May 2006 04:14:13 -0000      1.102
+++ lib/autoconf/status.m4      19 May 2006 21:01:31 -0000
@@ -660,7 +660,7 @@ echo 's/ $//
 [s,^[   #]*u.*,/* & */,]' >>conftest.defines
 
 # Break up conftest.defines:
-ac_max_sed_lines=m4_eval(_AC_SED_CMD_LIMIT - 3)
+ac_max_sed_lines=m4_eval(_AC_SED_CMD_LIMIT - 4)
 
 # First sed command is:         sed -f defines.sed $ac_file_inputs >"$tmp/out1"
 # Second one is:        sed -f defines.sed "$tmp/out1" >"$tmp/out2"